# this piece of code tries to dynamically add math operations
# such as addition (overloading the + operator using __add__) to an Integer class

def testSetattr(funcName):

    # acts like a int but reports on operations
    class Integer(object):
        def __init__(self, num):
            self._int = num

        def __repr__(self):
            return '({})'.format(self._int)

    # makes a wrapper for integer operations
    def makeFunctionality(funcName):
        def wrapper(self, other):
            # print 'running function with two arguments: {}({}, {})'.format(funcName, self, other)
            return Integer(self._int.__getattribute__(funcName)(other._int))
        return wrapper

    type.__setattr__(Integer, funcName, makeFunctionality(funcName))

    a = Integer(2)
    b = Integer(3)
    print id(funcName),
    print '   a.__add__(b)=', a.__add__(b),
    print '   a+b=', a+b


funcName1 = '__add__'
funcName2 = '__%s__' % 'add'
funcName3 = '__{}__'.format('add')

import sys
print sys.version
print 'are all the strings the same?  ' + str(funcName1 == funcName2 == funcName3)

testSetattr(funcName1)
testSetattr(funcName2)
testSetattr(funcName3)